Is filling the entire plot necessary? Cost explosion?

Hello everyone,

we are about to purchase the plot of land and are wondering if we are facing buying a barrel without a bottom.

Our future plot is located in a currently developing residential area. Currently, the infrastructure work is underway, and the gullies for wastewater have already been installed. Through the installation of the gullies, we have now noticed that we lie about 40 cm below the future street level with the entire plot area (approx. 27x24.5m) 663 sqm. Our concern is now that we have to raise the entire plot height by 40 cm. Is this really mandatory, or does only the area under the foundation slab need to be filled? The built-up area will be approx. 160 sqm.

For clarity, I am attaching pictures of the current situation. The gully is located in our future driveway, and the green area is the future plot with the adjacent neighboring house.

What preparatory work needs to be done, and what costs can one roughly expect?

Regards
Timo

No panic!

By placing the gullies, we have now noticed that with the entire plot area (approx. 27x24.5m) 663 sqm, we lie about 40 cm below the future street level.

What kind of terrain is that anyway? Is the "construction road" in the middle?

Our concern now is that we have to raise the entire plot height by 40 cm.

You don't have to do anything. The plot does not have to be level with the street.
It may have advantages, but if you look closely, there are many plots that are somewhat lower or sloped away from the street.
What should a mountain plot on the downhill side say?
So: everything you want, not must.

Is this really mandatory or does only the area under the foundation slab have to be filled?

Those of us in the flatlands should not panic. Many build the house about 30-40 cm higher as a precaution and then have 2-3 steps in front of their entrance door.
So: all good!
Everything else you should discuss with your building partner.

So I piled it up because I didn't want to be under the street - heavy rain says hello

but it doesn't cost the world now.

So I piled it up because I didn't want to be under the road - heavy rain says hello but that doesn't cost the world either.

Isn't soil often just thrown in afterwards with so many construction sites? Only the transport and filling cost something. If you have the right acquaintances, 1-2 cases of beer + a barbecue evening :-)

Calculate how a basement excavation would be distributed on your own property.

I would discuss it with the construction company how to solve this; the slope of the sewage pipe is important. I would also prefer to be above the level of the street myself. About 20cm. That way you don't need steps, but can pave gently sloping towards the street. Personally, I would build slightly higher than the street (without a basement). All around where there is supposed to be a garden, I would fill up with donated soil from other construction sites up to 20cm below the top edge of the lawn. The last few cm would be filled with topsoil. For the terrace, carport, and paved area accordingly without topsoil. There you need a mineral mixture/gravel.